WebRender newsletter #35

Bonsoir! Another week, another newsletter. I stealthily published WebRender on crates.io this week. This doesn’t mean anything in terms of API stability and whatnot, but it makes it easier for people to use WebRender in their own rust projects. Many asked for it so there it is. Everyone is welcome to use it, find bugs, report them, submit fixes and improvements even!

In other news we are initiating a notable workflow change: WebRender patches will land directly in Firefox’s mozilla-central repository and a bot will automatically mirror them on github. This change mostly affects the gfx team. What it means for us is that testing webrender changes becomes a lot easier as we don’t have to manually import every single work in progress commit to test it against Firefox’s CI anymore. Also Kats won’t have to spend a considerable amount of his time porting WebRender changes to mozilla-central anymore.
We know that interacting with mozilla-central can be intimidating for external contributors so we’ll still accept pull requests on the github repository although instead of merging them from there, someone in the gfx team will import them in mozilla-central manually (which we already had to do for non-trivial patches to run them against CI before merging). So for anyone who doesn’t work everyday on WebRender this workflow change is pretty much cosmetic. You are still welcome to keep following and interacting with the github repository.

Notable WebRender and Gecko changes

Jeff fixed a recent regression that was causing blob images to be painted twice.

Kats the work to make the repository transition possible without losing any of the tools and testing we have in WebRender. He also set up the repository synchronization.

Nical reduced the overdraw when rendering dashed corners, which was causing freezes in extreme cases.

Nical added the possibility to run wrench/scripts/headless.py (which lets us run CI under os-mesa) inside gdb, cgdb, rust-gdb and rr both with release and debug builds (see Debugging WebRender on wiki for more info about how to set this up).